Home video game systems may allow a game console to detect and respond to the motion of game controllers. More generally, a central controller can communicate with a set of remote devices that provide data to the central controller for real time processing. Several different technologies, including Bluetooth wireless technology, support this type of processing. More generally, wireless technologies may support electronics platforms that employ multiple remote controllers.
A conventional controller may support up to four wireless controllers that are commonly referred to as “remote controllers”. The four wireless controllers may be allocated in different ways. For example, one player may have four input points (e.g., right hand, left hand, right foot, left foot), or four players may each have a single input point. A remote controller may have controller buttons similar to those found on previous game controller pads. A remote controller may also have an internal motion sensor that accurately measures controller movement, orientation, and acceleration. Thus, the remote controllers may collect data to be transmitted to the central controller. For realistic game play without undesirable lags, the data needs to be transmitted to the central controller in a timely fashion. Therefore the remote controllers include circuitry to transmit controller data (e.g., button presses, controller movements) to the game console where the data can be processed to control the game console output (e.g., video game graphics).
Input latency is the delay between an action being taken at a controller (e.g., button press) and a corresponding action being taken by a program at the console (e.g., display avatar throwing ball). Since the quality of the game experience depends, at least in part, on how quickly a display can be updated to reflect an input at a remote controller, input latency is a concern for gaming systems. More generally, input latency can be a concern for other time slicing systems tasked with producing real time results based on input from multiple remote devices. Thus, input latency issues are not confined to gaming systems.
A central controller communicates with the set of remote controllers according to a time division multiplexing (TDM) scheme. In order to give each remote device a turn to communicate, and in order to satisfy input latency requirements, the central controller limits the number of devices to which time slices can be provided. If there are too many time slices, then conventionally the latency for responding to an input from a device may exceed a desired performance threshold. Based, at least in part, on a 16 ms frame refresh rate for a television, a conventional system imposes a limit of four controllers that are each provided with one time slice per 5 ms.
A conventional system may use Bluetooth (BT) technology for wireless communications. Bluetooth works efficiently and delivers acceptably low latency needed for “real-time applications” (e.g., video games) for a limited number of remote devices. While the BT specification allows for up to seven BT-enabled devices to communicate with a BT controller, some conventional systems only allow four remote controllers to communicate with the console. Thus, attempts to connect more than four remote controllers to a console while providing acceptable input latency given 16 ms television refresh rates have been undertaken. More generally, attempts to connect more than seven BT-enabled devices to a BT controller while providing acceptable input latency given real time application demands and/or device refresh rate demands have been attempted. Even more generally, attempts to connect a number of wireless devices to a wireless controller, where the number of wireless devices exceeds the number of devices that the wireless controller provides time slots for in a TDM scheme have been attempted.